Is finding batteries for your pocket calculator getting you down? You could get a solar calculator, but we know that sometimes you just want to add things up in a dark room. Enter the Shake-U-Later. You shake it from side to side, a magnet slides through a copper coil in plain view and electricity is generated. Something called Faraday’s Principle of Electromagnetic Energy does its magic, and you proceed to calculate your brains out. Ten minutes worth of mathematical power comes from 25 shakes, and batteries will just be a bad memory. It sells for 10 GBP ($ 15) at Gadgets.co.uk. Via – Productdose